Sainz exchanged times at the top of the timesheets with Leclerc and reigning world champion Max Verstappen on F1's return to Albert Park.

Verstappen headed the standings for much of the session with Red Bull opting to run the Dutchman on the softs for the duration of the session.

Once Ferrari switched to the softs, Leclerc immediately took to the top before Sainz eclipsed his teammate.

The Spaniard's top time was a 1m19.806s, half a second clear of Leclerc, who currently leads the drivers' championship going into this weekend's event. 

Sainz has openly admitted he's struggled to maximise Ferrari's 2022 challenger in the opening two grands prix of the season but looked at home in FP1.

The Ferrari driver nearly crashed when he switched back to the hards in the closing part of the session, struggling with oversteer on the exit of Turn 2.

Sainz's benchmark demonstrated how much quicker the revised Albert Park circuit is with his benchmark 3.7s quicker than Lewis Hamilton's top time from 2019.

Leclerc ensured it was a Ferrari 1-2 in opening practice, albeit 0.5s shy of his teammate's impressive benchmark.

Sergio Perez left it late in the Red Bull to go third after conducting various aero tests in the opening half of the session.

The Mexican set the best middle sector time of any driver in FP1 but lost out considerably - as did teammate Verstappen - in the final sector of the lap.

Verstappen classified fourth having dominated the early stages of the session, mainly due to being the only driver to run the soft tyre early on.

Pirelli has mixed it up for this weekend with there being a compound difference between the soft (C5) and medium (C3).

This should mean the soft is simply a qualifying tyre so it was no surprise to see Verstappen head the timesheets by a significant margin in the early stages.

Outside the top four, Lando Norris was fifth in an encouraging session for McLaren ahead of Alpine's Esteban Ocon.

Lewis Hamilton was seventh in the Mercedes, with the team opting not to introduce any upgrades for this weekend.

Hamilton is an Albert Park specialist, taking pole position at every race in Melbourne since 2014.

Daniel Ricciardo was eighth ahead of Fernando Alonso, who had a spin at Turn 11 in the final 20 minutes, while Valtteri Bottas rounded out the top 10 for Alfa Romeo.

Red flag drama

There was there fair share of red flag drama in opening practice in Melbourne with two stoppages.

The first was caused by a piece of debris falling off Perez's car, causing the session to be halted in the opening 20 minutes.

FP1 was then put on pause again when Sebastian Vettel stopped out on track on the exit of Turn 10 after his Aston Martin lost drive and began smoking.

The four-time champion was quick to get a fire extinguisher to put out any potential flames but his actions have resulted in a stewards investigation.

After the session, the FIA announced that Vettel is under investigation for "entering track without permission". 

Vettel ended the day 13th overall, a respectable effort given he was forced to miss Bahrain and Saudi Arabia because of coronavirus. 

He was just behind Yuki Tsunoda and George Russell in the final classification.

Sainz has also been called to the stewards for impeding Guanyu Zhou, who was 15th fastest, while Kevin Magnussen and Lance Stroll have also been summoned.

The Haas driver's participation was in doubt after he was feeling unwell ahead of the session.

Magnussen was still ahead of his teammate, 1.1s ahead of Schumacher who rounded out the 20 drivers in the opening practice.